Low Dose of BPA Induces Liver Injury through Oxidative Stress, Inflammation and Apoptosis in Long–Evans Lactating Rats and Its Perinatal Effect on Female PND6 Offspring

Bisphenol A (BPA) is a phenolic compound used in plastics elaboration for food protection or packaging. BPA-monomers can be released into the food chain, resulting in continuous and ubiquitous low-dose human exposure. This exposure during prenatal development is especially critical and could lead to alterations in ontogeny of tissues increasing the risk of developing diseases in adulthood. The aim was to evaluate whether BPA administration (0.036 mg/kg b.w./day and 3.42 mg/kg b.w./day) to pregnant rats could induce liver injury by generating oxidative stress, inflammation and apoptosis, and whether these effects may be observed in female postnatal day-6 (PND6) offspring. Antioxidant enzymes (CAT, SOD, GR, GPx and GST), glutathione system (GSH/GSSG) and lipid-DNA damage markers (MDA, LPO, NO, 8-OHdG) were measured using colorimetric methods. Inducers of oxidative stress (HO-1d, iNOS, eNOS), inflammation (IL-1β) and apoptosis (AIF, BAX, Bcl-2 and BCL-XL) were measured by qRT-PCR and Western blotting in liver of lactating dams and offspring. Hepatic serum markers and histology were performed. Low dose of BPA caused liver injury in lactating dams and had a perinatal effect in female PND6 offspring by increasing oxidative stress levels, triggering an inflammatory response and apoptosis pathways in the organ responsible for detoxification of this endocrine disruptor.Depto. de FisiologíaSección Deptal. de Bioquímica y Biología Molecular (Medicina)Fac. de MedicinaTRUEUnión Europea. Horizonte 2020Universidad Complutense de Madrid and Banco de Santanderpu

Comparing the Behavioural Effects of Exogenous Growth Hormone and Melatonin in Young and Old Wistar Rats

Growth hormone (GH) and melatonin are two hormones with quite different physiological effects. Curiously, their secretion shows parallel and severe age-related reductions. This has promoted many reports for studying the therapeutic supplementation of both hormones in an attempt to avoid or delay the physical, physiological, and psychological decay observed in aged humans and in experimental animals. Interestingly, the effects of the external administration of low doses of GH and of melatonin were surprisingly similar, as both hormones caused significant improvements in the functional capabilities of aged subjects. The present report aims at discerning the eventual difference between cognitive and motor effects of the two hormones when administered to young and aged Wistar rats. The effects were tested in the radial maze, a test highly sensitive to the age-related impairments in working memory and also in the rotarod test, for evaluating the motor coordination. The results showed that both hormones caused clear improvements in both tasks. However, while GH improved the cognitive capacity and, most importantly, the physical stamina, the effects of melatonin should be attributed to its antioxidant, anxiolytic, and neuroprotective properties

The role of cortical perforations in allogeneic block grafting for lateral augmentation in maxilla: A randomized clinical trial

Abstract Background: The need of decortication on the recipient site remains unclear for bone regeneration. To our knowledge, there are no human clinical trials that studied the influence of decortication on cancellous allogeneic block grafting. Purpose: The aim of the present study is to evaluate the influence of perforating the cortex of the recipient site on cancellous allogeneic block graft integration and revas- cularization in the maxilla. Material and Methods: Twenty-six patients referred for lateral bone augmentation were included in this clinical trial. Patients received freeze-dried bone allograft can- cellous blocks obtained from the iliac crest; cortical perforations of the recipient bed were performed in the test group while in the control group it was left intact. After a 4-month healing period another surgery was performed to place dental implants, and a bone biopsy was collected using a trephine. All samples underwent micro-CT scans, and were processed for histomorphometric and immunohistochemical analysis. Implant survival comparisons were made using a repeated measures analysis of vari- ance (ANOVA) while all other variables were compared using the analysis of covari- ance (ANCOVA). Results: One hundred and nineteen implants were placed into 110 augmented sites. One hundred percent implant survival rate was reported during 24 months follow-up period. No differences were reported in bleeding on probing at 1 (5.6 vs 9%) and 2 years (13.2 vs 12.1%), probing pocket depth at 1 (3.4 ± 0.95 vs 3.6 ± 1.12 mm) and 2 years (3.8 ± 1.02 vs 4.1 ± 1.46 mm), and marginal bone loss at 1 (0.2 ± 0.52 vs 0.3 ± 0.57 mm) and 2 years (0.6 ± 0.91 vs 0.5 ± 0.87 mm). No statistically significant dif- ferences were found in the micro-CT and histomorphometric analysis in terms of newly formed bone (25.7 ± 11.2% vs 22.3 ± 9.7%), soft tissue (33.0 ± 14.7% vs 36.5 ± 15.7%), remnant allograft (39.3 ± 20.4% vs 41.2 ± 22.7%), and bone mineralization (57.2 ± 10.6% vs 53.8 ± 8.7%). Perforating the cortex of the recipient site had no sig- nificant effect on angiogenesis as shown by immunohistochemical analysis of CD34 positive blood vessels (39.21 ± 10.53/mm2 vs 34.16 ± 12.67/mm2). Conclusion: Cancellous allogeneic bone block grafts are a clinically acceptable alter- native for horizontal bone augmentation. Cortical perforations of the recipient site in the maxilla did not improve angiogenesis nor bone formation within the block graft.Depto. de Especialidades Clínicas OdontológicasFac. de OdontologíaTRUEpu

Effect of chronic melatonin administration on several physiological parameters from old Wistar rats and SAMP8 mice

The effect of melatonin administration on age-induced alterations in hepatocytes, central nervous system, immune system, and skin are reviewed. Twenty-two-month-old Wistar rats and SAMP8 (senescence prone) mice of 10 months of age were used as experimental models. Wistar rats were analyzed untreated or after the chronic administration of melatonin at a dose of 1 mg/kg/day in the drinking water for 10 weeks. At the end of the treatment period, the various parameters were investigated. Results were compared with those of 2-month-old controls. In hepatocytes, aging induced a significant increase in oxidative stress, inflammation, and apoptosis when compared to young animals. Melatonin administration significantly ameliorated all these age-related changes. The impairment of the cardiovascular system with aging appears to contribute to the increased morbidity and mortality of the aged subjects. The process was investigated in SAMP8 mice of 10 months of age. Melatonin was provided for 30 days at two different dosages (1 mg/kg/day and 10 mg/kg/day), also in the drinking water. After treatment, the expression of inflammatory mediators (tumor necrosis factor-α, interleukin 1 and 10, NFκBp50 and NFκBp52), apoptosis markers (BAD, BAX, and Bcl2), and parameters related to oxidative stress (heme oxygenases 1 and 2, endothelial and inducible nitric oxide synthases) were determined in the heart. Inflammation as well as oxidative stress and apoptosis markers were increased in old SAMP8 males, as compared to young controls. After treatment with melatonin, these age-altered parameters were partially reversed. The results suggest that oxidative stress and inflammation increase with aging and that chronic treatment with melatonin is able to reduce these parameters. In the skin, a reduction of epidermal thickness together with a marked increase of the hypodermis with great fat accumulation was observed in old rats, together with an increase in caspase 3, 8 of nucleosomes and LPO and a reduction in Bcl2 levels in the cultured keratinocytes. Melatonin treatment was able to reduce the fat content of the hypodermis and to increase Bcl2 and reduce nucleosomes, caspases, and LPO in keratinocytes. Conclusion: Melatonin administration exerts a beneficial effect against age-induced changes in several physiological parameters in Wistar rats and SAMP 8 mice.Instituto de Salud Carlos IIIDepto. de FisiologíaFac. de MedicinaTRUEpu

Split bone block technique: 4-month results of a randomised clinical trial comparing clinical and radiographic outcomes between autogenous and xenogeneic cortical plates

Purpose: To evaluate short-term clinical and radiographic outcomes of bone regeneration procedures using thin cortical porcine xenogeneic bone plates in combination with autogenous bone chips compared with thin autogenous cortical plates and autogenous bone chips. Materials and methods: A total of 19 patients (12 women and 7 men, mean age 58.24 ± 3.09 years) were randomly allocated to two different groups regarding surgical procedure: autogenous cortical plates (ACP group) and xenogeneic cortical plates (XCP group). Preoperative CBCT scans were performed for each patient. Surgical time and postoperative pain were recorded, as well as tissue healing and graft resorption after 4 months, then another surgical procedure was performed to place dental implants. Data were analysed using an analysis of covariance. Results: Twenty-one surgical procedures were performed on 19 patients (10 from the XCP group and 9 from the ACP group). The operative time was significantly lower in the XCP group (25.45 ± 3.88 minutes) than in the ACP group (44.10 ± 3.60 minutes). The XCP group also showed less pain, but not significantly less, than the ACP group. The graft resorption rate in the ACP and XCP groups was 2.03 ± 1.58% and 3.49 ± 2.38% respectively, showing no statistically significant difference. Conclusions: Despite the limited sample size and non-uniform distribution between the maxilla and mandible as surgical sites, the results suggest that XCP and ACP grafts are similar in terms of bone volume gain and graft resorption rate, with no significant differences in wound healing or complication rate. Nevertheless, the XCP group recorded lower pain levels and required significantly less operative time compared to the ACP group.Depto. de Especialidades Clínicas OdontológicasFac. de OdontologíaTRUEpu

Growth hormone prevents neuronal loss in the aged rat hippocampus

Decline of growth hormone (GH) with aging is associated to memory and cognitive alterations. In this study, the number of neurons in the hilus of the dentate gyrus has been assessed in male and female Wistar rats at 3, 6, 12, 14, 18, 22 and 24 months of age, using the optical fractionator method. Male rats had more neurons than females at all the ages studied. Significant neuronal loss was observed in both sexes between 22 and 24 months of age. In a second experiment, 22 month-old male and female rats were treated for 10 weeks with 2 mg/kg/day of GH or saline. At 24 months of age, animals treated with GH had more neurons in the hilus than animals treated with saline. These findings indicate that GH is neuroprotective in old animals and that its administration may ameliorate neuronal alterations associated to aging. © 2004 Elsevier Inc. All rights reserved.Peer Reviewe

Causes, characteristics and consequences of anovulatory follicles in superovulated sheep

Efficiency of superovulatory protocols is affected by the occurrence of reproductive abnormalities, such as the presence of anovulatory follicles. The objective of current study was to assess the incidence and possible causes of anovulatory follicles in superovulated sheep, in order to characterize the endocrine functionality of these follicles in terms of estradiol production and to evaluate their relationship with development of embryos from other follicles. The number and size of all follicles present in the ovaries of 12 sheep treated with a superovulatory FSH step-down treatment was assessed by ultrasonography. On Day 3 after subsequent estrus behaviour, the number of corpora lutea and anovulatory follicles were recorded and the fluid of anovulatory follicles ≥5 mm in size was aspirated and assayed for estradiol. At once, embryos were recovered to evaluate their viability. In current study, anovulatory structures averaged 34.6% of the follicles developing to preovulatory sizes. The number of anovulatory follicles was determined by the existence of follicular dominance effects, since they increased with a higher difference in size between the largest and the second largest follicle at the beginning of the superovulatory treatment (P < 0.05, r2 = 0.420). Most of the anovulatory follicles showed signs of functionality failures, indicated by a low mean estradiol concentration (9.9 ± 1.1 ng/ml). However, a 22.4% of them were highly estrogenic (>200 ng/ml) and their permanence beyond the ovulation was related to a drop in the embryo viability rate (P < 0.005), leading to decreased final superovulatory yields. © 2005 Elsevier Inc. All rights reserved

Estradiol and soy extract increase the production of new cells in the dentate gyrus of old rats

In young rodents, estradiol increases cell proliferation in the dentate gyrus of the hippocampus. However, it is unknown if the old brain retains this response to estradiol. Here we assessed the generation of new cells in the dentate gyrus of old rats after administration of estradiol or a soy extract, since soy is used as an alternative to hormonal replacement therapy in postmenopausal women. In a first experiment, 12-month-old animals were ovariectomized and studied at 14, 18 or 22 months of age. The production of new cells, assessed by the incorporation of bromodeoxyuridine (BrdU), was similar in 14- and 18-month-old rats. However, there was a significant reduction in the number of BrdU-immunoreactive cells at 22 months of age. In a second experiment, 22-month-old ovariectomized animals were treated for 10 weeks with a weekly s.c. injection of 150 μg estradiol valerianate or with 60 mg/kg per day soy extract added to the drinking water. Both treatments increased significantly the production of new cells in the dentate gyrus. These findings indicate that the brains of old rats retain the ability to increase the production of new cells in response to estradiol and soy extracts. © 2005 Elsevier Inc. All rights reserved.Peer Reviewe

Periosteal Pocket Flap technique for lateral ridge augmentation. A comparative pilot study versus guide bone regeneration

Background: Implant rehabilitation of posterior mandibular defects is frequently associated to a horizontal bone loss. There exist several regenerative techniques to supply this bone deficiency, one of which is the Periosteal Pocket Flap Technique (PPF) proposed by Steigmann et al. to treat small horizontal bone defects. The present study proposes a modification of this technique based on the concurrent use of PPF with the use of xenogeneic and autologous bone and Plasma Rich in Growth Factors (PRGF). The aim of this study is to evaluate clinical and radiographic outcomes of the PPF with the use of xenogeneic and autologous bone and PRGF in comparison with conventional Guided Bone Regeneration (GBR) procedures. Methods: Nine patients were enroled in the study (7 women and 2 men, mean age: 53 ± 2.74 years) and allocated to PPF or GBR. In both groups implant placement was performed simultaneously to bone regeneration. Preoperative CBCT scans were performed for each patient. Surgical time and postoperative pain were recorded, as well as tissue healing. Moreover, horizontal bone gain (mm), graft surface area (mm2) and graft volume (mm3) were evaluated. Results: Nine surgeries were performed: 6 PPF and 3 GBR. Regarding clinical outcomes, operative time was significative greater in GBR group than in PPF group (51.67 ± 3.51 min vs. 37 ± 5.69 min; p = 0.008). Postoperative pain was higher in GBR compared to PPF (p = 0.011). Regarding radiographical results, there were not significant differences in horizontal bone gain (PPF: 9.43 ± 1.8 mm; GBR: 9.28 ± 0.42 mm), surface area (PPF: 693.33 ± 118.73 mm2; GBR: 655.61 ± 102.43 mm2), and volume (PPF: 394.97 ± 178.72 mm3; GBR: 261.66 ± 118 mm3) between groups. Conclusions: This prospective study demonstrates that the combination of autograft/xenograft and PRGF in PPF technique is a simpler, cheaper, and faster technique than GBR technique for achieving moderate lateral bone augmentation in implant treatment. Future randomised clinical studies are needed to confirm the results.Depto. de Especialidades Clínicas OdontológicasFac. de OdontologíaTRUEpu

Clinical and radiographic outcomes of allogeneic block grafts for maxillary lateral ridge augmentation: A randomized clinical trial

Abstract Background: A main drawback of bone block graft surgery is the resorption occurring in early stages of healing. To our knowledge, there are no studies comparing out- comes of freeze-dried bone allograft (FDBA) blocks with different architecture. Purpose: The aim of this work was to investigate different factors that can affect graft resorption and to compare the resorption rates of two different types of alloge- neic blocks, corticocancellous and cancellous. Materials and Methods: A randomized clinical trial was designed. Twenty-eight patients referred for onlay bone augmentation prior to implant placement were included in the study. Preoperative computerized tomography (CT) was taken for all patients. Patients received FDBA blocks of either cancellous or corticocancellous bone obtained from the iliac crest. After a 4-month follow-up, postoperative CT was taken. Then, another surgery was performed, with the purpose to place dental implants. The aforementioned groups were compared for bone resorption and implant outcome using analysis of covariance (ANCOVA) and repeated ANOVA mea- sures, respectively. Demographic data, trabecular bone density, and graft sites were also analyzed. Results: A total of 93 implants were placed in the augmented bone sites over 28 patients. A 100% survival rate was achieved during a mean follow-up period of 24 months in both groups. Higher bone resorption rate was found with cancellous bone grafts (29.2%±2.6) compared with corticocancellous grafts (19.3%±2.3). Moreover, higher resorption rates in patients with lower bone density (185 Hounsfield Units) (16.8% ± 2.1) and nonsmokers (22.1% ± 2.3), respectively. Conclusion: Within the limitations of this study, these findings indicate that both corticocancellous and cancellous FDBA grafts constitute a clinical acceptable alterna- tive for bone reconstruction, although cancellous grafts present higher resorption rates. Moreover, host factors such as patient's low bone density and smoking habits may also increase graft resorption rates.Depto. de Especialidades Clínicas OdontológicasFac. de OdontologíaTRUEpu